RESUMO
High-power terahertz (THz) quantum cascade laser, as an emerging THz solid-state radiation source, is attracting attention for numerous applications including medicine, sensing, and communication. However, due to the sub-wavelength confinement of the waveguide structure, direct beam brightness upscaling with device area remains elusive due to several mode competition and external optical lens is normally used to enhance the THz beam brightness. Here, we propose a metallic THz photonic crystal resonator with a phase-engineered design for single mode surface emission over a broad area. The quantum cascade surface-emitting laser is capable of delivering an output peak power over 185 mW with a narrow beam divergence of 4.4° × 4.4° at 3.88 THz. A high beam brightness of 1.6 × 107 W sr-1m-2 with near-diffraction-limited M2 factors of 1.4 in both vertical and lateral directions is achieved from a large device area of 1.6 × 1.6 mm2 without using any optical lenses. The adjustable phase shift between the lattices enables a stable and high-intensity surface emission over a broad device area, which makes it an ideal light extractor for large-scale THz emitters. Our research paves the way to high brightness solid-state THz lasers and facilitates new applications in standoff THz imaging, detection, and diagnosis.
RESUMO
Topological lasers (TLs) have attracted widespread attention due to their mode robustness against perturbations or defects. Among them, electrically pumped TLs have gained extensive research interest due to their advantages of compact size and easy integration. Nevertheless, limited studies on electrically pumped TLs have been reported in the terahertz (THz) and telecom wavelength ranges with relatively low output powers, causing a wide gap between practical applications. Here, we introduce a surface metallic Dirac-vortex cavity (SMDC) design to solve the difficulty of increasing power for electrically pumped TLs in the THz spectral range. Due to the strong coupling between the SMDC and the active region, robust 2D topological defect lasing modes are obtained. More importantly, enough gain and large radiative efficiency provided by the SMDC bring in the increase of the output power to a maximum peak power of 150 mW which demonstrates the practical application potential of electrically pumped TLs.
Assuntos
Meios de Contraste , Albumina Sérica , Humanos , Meios de Contraste/efeitos adversos , Albumina Sérica/análise , Albumina Sérica/metabolismo , Masculino , Feminino , Nitrogênio da Ureia Sanguínea , Valor Preditivo dos Testes , Idoso , Doença das Coronárias/sangue , Nefropatias/induzido quimicamente , Nefropatias/sangue , Pessoa de Meia-IdadeAssuntos
Ansiedade , Depressão , Falência Renal Crônica , Diálise Renal , Humanos , Diálise Renal/psicologia , Falência Renal Crônica/terapia , Falência Renal Crônica/complicações , Falência Renal Crônica/psicologia , Depressão/etiologia , Ansiedade/etiologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , AdultoRESUMO
The pleiotropic effects of TGR5 make it an appealing target for intervention of metabolic and inflammatory disorders, but systemic activation of TGR5 faces challenges of on-target side effects, especially gallbladder filling. Gut-restricted agonists were proved to be sufficient to circumvent these side effects, but extremely low systemic exposure may not be effective in activating TGR5 since it is located on the basolateral membrane. Herein, to balance potency and physicochemical properties, a series of gut-restricted TGR5 agonists with diversified kinetophores had been designed and synthesized. Compound 22-Na exhibited significant antidiabetic effect, and showed favorable gallbladder safety after 7 days of oral administration in humanized TGR5H88Y mice, confirming that gut-restricted agonism of TGR5 is a viable strategy to alleviate systemic target-related effects.
Assuntos
Ácido Betulínico , Receptores Acoplados a Proteínas G , Camundongos , Animais , Receptores Acoplados a Proteínas G/metabolismo , Hipoglicemiantes/farmacologia , Vesícula Biliar/metabolismoAssuntos
Inteligência Artificial , Reumatologia , Humanos , Relações Médico-Paciente , Idioma , Doenças ReumáticasAssuntos
Fragilidade , Falência Renal Crônica , Insuficiência Renal Crônica , Humanos , Fragilidade/epidemiologia , Fragilidade/complicações , Estudos Transversais , Prevalência , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , Falência Renal Crônica/complicaçõesRESUMO
Many molecules have broad fingerprint absorption spectra in mid-wave infrared range which requires broadly tunable lasers to cover the interested spectrum in one scan. We report a strain-balanced, InAlAs/InGaAs/InP quantum cascade laser structure based on diagonal transition active region with high output power and and wide tuning range at λ â¼ 8.9 µm. The maximum pulsed optical power and the wall-plug efficiency at room temperature are 4 W and 11.7%, respectively. Maximum continuous wave double-facet power is 1.2 W at 25 °C for a 4 mm by 9 µm laser mounted epi-side down on a diamond/copper composite submount. The maximum pulsed and continuous wave external-cavity tuning range are from 7.71 µm to 9.15 µm and from 8 µm to 8.9 µm, respectively. The continuous wave power of the external cavity mode exceeds 200â mW across the entire spectrum.
RESUMO
Microresonator-based high-speed single-mode quantum cascade lasers are ideal candidates for on-chip optical data interconnection and high sensitivity gas sensing in the mid-infrared spectral range. In this paper, we propose a high frequency operation of single-mode doughnut-shaped microcavity quantum cascade laser at â¼4.6â µm. By leveraging compact micro-ring resonators and integrating with grounded coplanar waveguide transmission lines, we have greatly reduced the parasitics originating from both the device and wire bonding. In addition, a selective heat dissipation scheme was introduced to improve the thermal characteristics of the device by semi-insulating InP infill regrowth. The highest continuous wave operating temperature of the device reaches 288â K. A maximum -3â dB bandwidth of 11â GHz and a cut-off frequency exceeding 20â GHz in a microwave rectification technique are obtained. Benefiting from the notch at the short axis of the microcavity resonator, a highly customized far-field profile with an in-plane beam divergence angle of 2.4° is achieved.